English

The tropical symplectic Grassmannian

Combinatorics 2021-10-18 v2 Symplectic Geometry

Abstract

We launch the study of the tropicalization of the symplectic Grassmannian, that is, the space of all linear subspaces that are isotropic with respect to a fixed symplectic form. We formulate tropical analogues of several equivalent characterizations of the symplectic Grassmannian and determine all implications between them. In the process, we show that the Pl\"ucker and symplectic relations form a tropical basis if and only if the rank is at most 2. We provide plenty of examples that show that several features of the symplectic Grassmannian do not hold after tropicalizing. We show exactly when do conormal fans of matroids satisfy these characterizations, as well as doing the same for a non-constant coefficient generalization. Finally, we propose several directions to extend the study of the tropical symplectic Grassmannian.

Keywords

Cite

@article{arxiv.2103.16512,
  title  = {The tropical symplectic Grassmannian},
  author = {George Balla and Jorge Alberto Olarte},
  journal= {arXiv preprint arXiv:2103.16512},
  year   = {2021}
}

Comments

28 pages, 7 figures

R2 v1 2026-06-24T00:42:06.658Z